Ofloxacin (OFLX) was administered at a dose of 200 mg, three times daily (600 mg) for 14 days, to 15 patients suffering from complicated urinary tract infection. According to the criteria for clinical evaluation by the UTI committee, excellent and moderate responses were seen in 54% at 5 days evaluation, and in 91% at 14 days evaluation. No serious side effects were recognized and no changes in laboratory examination data were observed. We conclude that OFLX was useful in treatment of urinary tract infection.